diff --git a/servers/ruby/Gemfile b/servers/ruby/Gemfile
index 6404685..c859241 100644
--- a/servers/ruby/Gemfile
+++ b/servers/ruby/Gemfile
@@ -9,7 +9,7 @@ gem 'graphql'
 # Bundle edge Rails instead: gem 'rails', github: 'rails/rails'
 gem 'rails', '~> 5.0.7', '>= 5.0.7.2'
 # Use Puma as the app server
-gem 'puma', '~> 3.0'
+gem 'puma', '~> 3.12'
 # Use SCSS for stylesheets
 gem 'sass-rails', '~> 5.0'
 # Use Uglifier as compressor for JavaScript assets
diff --git a/servers/ruby/Gemfile.lock b/servers/ruby/Gemfile.lock
index 42588dd..80725d9 100644
--- a/servers/ruby/Gemfile.lock
+++ b/servers/ruby/Gemfile.lock
@@ -83,7 +83,7 @@ GEM
     nio4r (2.3.1)
     nokogiri (1.10.4)
       mini_portile2 (~> 2.4.0)
-    puma (3.12.1)
+    puma (3.12.2)
     rack (2.0.7)
     rack-test (0.6.3)
       rack (>= 1.0)
@@ -167,7 +167,7 @@ DEPENDENCIES
   jbuilder (~> 2.5)
   jquery-rails
   listen (~> 3.0.5)
-  puma (~> 3.0)
+  puma (~> 3.12)
   rails (~> 5.0.7, >= 5.0.7.2)
   sass-rails (~> 5.0)
   spring